• Steel and Composite Structures
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• v.7 no.5
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• pp.355-376
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• 2007

The purpose of this study is to predict and investigate the time-dependent creep behavior of composite materials. For this, firstly the evaluation method for the modulus of elasticity of whole fiber and matrix is presented from the limited information on fiber volume fraction using the singular value decomposition method. Then, the effects of fiber volume fraction on modulus of elasticity of GFRP are verified. Also, as a creep model, the nonlinear curve fitting method based on the Marquardt algorithm is proposed. Using the existing Findley's power creep model and the proposed creep model, the effect of fiber volume fraction on the nonlinear creep behavior of composite materials is verified. Then, for the time-dependent analysis of a composite material subjected to uniaxial tension and simple shear loadings, a user-provided subroutine UMAT is developed to run within ABAQUS. Finally, the creep behavior of center loaded beam structure is investigated using the Hermitian beam elements with shear deformation effect and with time-dependent elastic and shear moduli.

• Asia pacific journal of information systems
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• v.31 no.3
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• pp.392-414
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• 2021

Social networking services (SNS) is an indispensable method in order to obtain information of the Internet participants. The study identified three variables of social media communication, sharing culture, and online trust in terms of social capital theory (SCT) and reviewed intention& behavior variables in terms of theory of planned behavior (TPB). The data were collected from 330 samples of SNS user, and were involved, and the research model uses AMOS to make confirmatory factor analysis. The findings confirmed our hypothesis that social media communication, sharing culture, and online trust affect individuals' behaviors to sharing information. This study emphasizes that not only social media communication but also sharing culture to SNS can stimulate information sharing. while previous research has predominately focused on personal cognition or social network, the study examines the integrated influence of communication, culture and trust on information sharing in SNS. In sum, by explicating the unique role of social capital, this paper aims at contributing to the continued development and success of SNS in general.

• Tribology and Lubricants
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• v.32 no.6
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• pp.207-211
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• 2016

To interpret the perception that originates from tactile sensibility during people touch and recognize the object surfaces, this study focuses on the development of a friction model that can describe the interaction of a stylus pen sliding over the counter surfaces. In addition, the study includes several other experimental factors such as the pressure, temperature, and topology of surface, which can have an effect on the emotional user experience concerning various surfaces; this research aims to suggest a method to quantitatively evaluate the relation between these experimental parameters and emotional user experience. Accordingly, the objective of research comprises the friction characteristic technology for measurement of fine tribological behavior and a standard to quantify the emotional feedback. Existing panels or input devices that provide interaction feedback about user actions simply operate with a single frequency vibration or sound response. On the contrary, this research investigates various interaction characteristics including friction force, frequency, and surface topology synthetically. Using the developed model, which can explain the relation between the friction parameters and emotional user experience, developers can design their product in order to provide the user with expected emotional sensibility. Consequently, it can contribute to reduce the development cost about sensitivity model.

• Steel and Composite Structures
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• v.10 no.2
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• pp.129-149
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• 2010

The objective of this study is to formulate a general 3D material-structural analysis framework for the thermomechanical behavior of steel-concrete structures in a fire environment. The proposed analysis framework consists of three sequential modeling parts: fire dynamics simulation, heat transfer analysis, and a thermomechanical stress analysis of the structure. The first modeling part consists of applying the NIST (National Institute of Standards and Technology) Fire Dynamics Simulator (FDS) where coupled CFD (Computational Fluid Dynamics) with thermodynamics are combined to realistically model the fire progression within the steel-concrete structure. The goal is to generate the spatial-temporal (ST) solution variables (temperature, heat flux) on the surfaces of the structure. The FDS-ST solutions are generated in a discrete form. Continuous FDS-ST approximations are then developed to represent the temperature or heat-flux at any given time or point within the structure. An extensive numerical study is carried out to examine the best ST approximation functions that strike a balance between accuracy and simplicity. The second modeling part consists of a finite-element (FE) transient heat analysis of the structure using the continuous FDS-ST surface variables as prescribed thermal boundary conditions. The third modeling part is a thermomechanical FE structural analysis using both nonlinear material and geometry. The temperature history from the second modeling part is used at all nodal points. The ABAQUS (2003) FE code is used with external user subroutines for the second and third simulation parts in order to describe the specific heat temperature nonlinear dependency that drastically affects the transient thermal solution especially for concrete materials. User subroutines are also developed to apply the continuous FDS-ST surface nodal boundary conditions in the transient heat FE analysis. The proposed modeling framework is applied to predict the temperature and deflection of the well-documented third Cardington fire test.

• International Commerce and Information Review
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• v.11 no.3
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• pp.101-123
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• 2009

This research which applied with Uses and Gratification Theory tried the comparative analysis between internet purchasers and internet non-purchasers by the user's motivation, attitudes, and behavior in Mongolia, By utilizing the two-group discriminant analysis method, which tested the hypotheses of this study. In Internet Market of Mongolia, This research classifies all internet consumers into internet purchasers, and non-internet purchasers and examines the differences in motivations, behaviors, and attitudes between the two groups; based on the assumption that these two groups have different needs and expectations while using the internet. The two group discriminant analysis was conducted to identify a lot of differences between the two groups. Research results show that important differences are found in motivations for using the Internet, attitudes toward the Internet, amount of Internet usage, and frequency of visiting a certain type of Web site. In the practical aspect, This result provides an understanding of the Mongolia Internet shopping, also it could give some valuable implication for the Internet company marketers who are trying to find out how to penetrate into Mongolia internet market.

• KSII Transactions on Internet and Information Systems (TIIS)
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• v.17 no.9
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• pp.2529-2549
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• 2023

For effectively lowering down the risk of cyber threating, the zero-trust architecture (ZTA) has been gradually deployed to the fields of smart city, Internet of Things, and cloud computing. The main concept of ZTA is to maintain a distrustful attitude towards all devices, identities, and communication requests, which only offering the minimum access and validity. Unfortunately, adopting the most secure and complex multifactor authentication has brought enterprise and employee a troublesome and unfriendly burden. Thus, authors aim to incorporate machine learning technology to build an employee behavior analysis ZTA. The new framework is characterized by the ability of adjusting the difficulty of identity verification through the user behavioral patterns and the risk degree of the resource. In particular, three key factors, including one-time password, face feature, and authorization code, have been applied to design the adaptive multifactor continuous authentication system. Simulations have demonstrated that the new work can eliminate the necessity of maintaining a heavy authentication and ensure an employee-friendly experience.

• Journal of the Korean housing association
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• v.18 no.3
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• pp.19-29
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• 2007

This study is aimed at interpreting into changes and characters of function applied into quantative analysis in ubiquitous house. Digital technology being introduced into architectural fields, It applied expansively from design and construction to user's convenience. The application of digital technology is presented to various change like effectiveness and exactness in design and function of space, which is overlayed digital space to physical space beyond the extent of receiving human needs in physical space. In ubiquitous house, digital technologies are supplied to function coordinated with life, appreciating into positional informations of human and materials, spatial informations. Ubiquitous house is comparably effective into funtional expansion, user's convenience, safty, which, for the future, is going to using on housing of high performance encouraging the application of advanced technology. Therefore this study is classified into human behaviors, functions, performances and characters of digital system in ubiquitous house, which being established into the relation of elements, is interpreted numerically into functional changes and charats being applied to ARM.

• Journal of the Korea Institute of Information Security & Cryptology
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• v.24 no.1
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• pp.135-144
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• 2014

Since anti-forensics have been developed in order to avoid digital forensic investigation, the forensic methods for analyzing anti-forensic behaviors have been studied in various aspects. Among the factors for user activity analysis, "Iconcache.db" files, which have the icon information of applications, provides meaningful information for digital forensic investigation. This paper illustrates the features of IconCache.db files and suggests the countermeasures against anti-forensics utilizing them.

• Tribology and Lubricants
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• v.23 no.3
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• pp.109-116
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• 2007

A scroll compressor is on the increase in the use for the cooling and ambition machinery because of the advantages about high efficiency, low vibration and low noise. The design of thrust bearing for scroll compressor has depended on the experience. The lubrication considering the squeeze flow was applied for high side shell and low side shell of scroll thrust bearing. This work was based on governing fluid lubrication equation at the general coordinate. It shows the behavior for an orbiting scroll with direct numerical analysis using FDM. This study obtained the theoretical design value by finding load capacity and tilting angle of an orbiting scroll for thrust bearing in a scroll compressor. Especially this work performed the analysis about the design parameter. The program was written using Visual C++ to enhance user to change the design parameter easily. In particular the result value and the pressure profile were displayed as windows in every step for user to understand without difficulty.

• Journal of Information Processing Systems
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• v.7 no.1
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• pp.209-220
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• 2011

One of the major factors influencing the phenomenal growth of the smart phone market is the active development applications based on open environments. Despite difficulties in finding and downloading applications due to the small screens and inconvenient interfaces of smart phones, users download applications nearly every day. Such user behavior patterns indicate the significance of smart phone applications. So far, studies on applications have focused mainly on technical approaches, including recommendation systems. Meanwhile, the issue of culture, as an aspect of user characteristics regarding smart phone use, remains largely unexamined throughout the world. Hence, the present study attempts to analyze the highest ranked smart phone applications downloaded and paid for that are ranked the highest in 10 countries (Korea, Japan, China, India, the UK, USA, Indonesia, Canada, France, and Mexico) and we then derive the CDSC (Cultural Dimensions Score of Content) for these applications. The results derived are, then, mapped to the cultural dimensions model to determine the CISC (Cultural Index Score for Country). Further, culturally significant differences in smart phone environments are identified using MDS analysis.